| Abstract [eng] |
In this final project several welding techniques have been compared with ultrasonic welding. The results from ultrasonic welding of plastic wedge dowels with different particle boards and fiber boards were described, and joint quality analysis was performed. All of this has been done to add more knowledge to a little–researched topic – ultrasonic welding of thermoplastics in wood, and to facilitate the integration of the process into production of a company, speed up the training of employees and increase the productivity of their labor. A great deal of information has been gathered on the welding process, the parameters on which it depends. Research related to this topic has been discussed and engineering methods have been analyzed. The experimental part describes the research process, how everything was done, describes the equipment used for measuring humidity, pulling out the wedge dowels, ultrasonic welding and insertion of wedge dowels equipment, the operating cycle and materials that have been used in the process. During the study, visual inspection was performed after each welding operation of the thermoplastic wedge dowels and wedge dowel extraction tests were performed to evaluate the strength characteristics of the joints. The obtained results were also compared with the observations discussed by other researchers in other articles and were proved to be correct. There was a tendency found of parameters that related the depth of the drilled holes (cavity area sizes) with the pull–out forces of the wedge dowels in different wood boards. After the study was finished, recommendations were made for future research and it was concluded that the quality of the welded joint is mainly influenced by the density of the wood board, the quality of particle bonding, the geometry of the drilled hole, the density and size of the cavities inside the drilled hole. |
